Abstract
We fabricated nanostructured Ge films using Ar and He radio-frequency magnetron plasma sputtering deposition. Monodisperse
amorphous Ge nanoparticles of 30-50 nm size were arranged without aggregation in the high-gas-pressure range of 500 Torr. The Ge
film porosity was as high as 15-30%. We tested the charge/discharge cycle performance of Li-ion batteries with nanostructured Ge
and GeSn anodes. The Ge anode with a dispersed arrangement of nanoparticles showed a Li-storage capacity of 565 mAh/g after the
60th cycle. The capacity retention was markedly improved by the addition of 3 at% Sn in Ge anode. The GeSn anode （3 at% Sn）
achieved a higher capacity of 1128 mAh/g after 60 cycles with 92% capacity retention. Precise control of the nano-morphology by a
single step procedure using low temperature plasma is effective for stable cycling of high-capacity Ge anodes.
